Acute and chronic pulmonary effects are being looked for in firefighters intermittently exposed to high level smoke exposure. A large group of firefighters is being studied by annual questionnaires and pulmonary function tests. In addition, environmental analysis is taking place looking for type and quantity of different pollutants. The longitudinal decrement in pulmonary function will be correlated with frequency and severity of exposure to various pulmonary irritants. This year the entire fire department will be restudied. Special studies of acute smoke inhalation effects and possible cardiac effects of CO and other pollutants will be conducted.